Over the past 20 years smartphones have become omnipresent in modern society. Because of their cost and importance to their users, ways have been sought for protecting smartphones against damage in the event that they are dropped or subjected to severe impacts or other physical shocks. In this regard, protective cases have been developed for covering the sides and rear surfaces of smartphones. See, for example, the two-piece case of U.S. Pat. No. 8,190,222B2, the one-piece case with cushion inserts at the corners of U.S. Pat. No. 8,909,309B2, the one-piece case of three-layers with three different hardnesses of U.S. Pat. No. 9,281,858B2, and the one-piece case of U.S. Pat. No. 9,526,320B2 with a sidewall of a layer of a flexible polymer and a layer of a damping material having a plurality of inwardly and outwardly projecting protrusions.
However, a one-piece case to better protect smartphones against damage from falls and other shocks has continued to be sought.